ScholarWorks@동국대학교

초록

Virus-like particles (VLPs) offer a versatile platform for biomedical applications owing to their uniform nanoscale architecture, structural stability, and amenability to surface engineering. In this study, we developed an antibodybinding VLP by genetically inserting the Staphylococcus aureus protein A B domain into the major immunodominant region loop of the hepatitis B virus core antigen (HBcAg). The resulting HBcAg-B fusion protein was successfully expressed in Escherichia coli, predominantly in the soluble fraction and efficiently purified using His-tag affinity chromatography. Sucrose density gradient ultracentrifugation and transmission electron microscopy (TEM) confirmed that the HBcAg–B proteins self-assembled into well-defined VLPs with diameters of approximately 30-35 nm, comparable to native HBcAg VLPs, indicating that B domain insertion did not compromise capsid assembly or structural integrity. TEM analysis provided direct visual evidence of Fc-mediated antibody immobilization on the VLP surface, revealing multivalent antibody binding at the particle level. Surface plasmon resonance analysis further demonstrated specific and reversible antibody binding with a moderate nanomolar affinity (KD ≈ 144 nM), consistent with protein A–Fc interactions. Collectively, these results establish HBcAg–B VLPs as a structurally robust and functionally competent nanoplatform for oriented and multivalent antibody immobilization, highlighting their potential as modular carriers for therapeutic antibody delivery.

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